In 2004 Michael Grade successfully lobbied then culture secretary Tessa Jowell for what became the BBC Trust. Photograph: Linda Nylind for the Guardian

Created in the aftermath of the Hutton report, which led to the resignation of the broadcaster's chairman and director general, the BBC Trust has struggled to solve the very problem it was designed to avoid.

It appeared logical to replace the old BBC board of governors after the chairman, Sir Gavyn Davies, who had resolutely backed Greg Dyke in the Iraq dossier row with the Labour government, quit on the same day as the director general in January 2004 following serious criticism of the corporation's journalism in Lord Hutton's report.

But resisting calls for an independent regulator to replace the board of governors, Davies' successor, Michael Grade, successfully lobbied then culture secretary Tessa Jowell for what became the BBC Trust, arguing it should "follow the money" and be responsible for safeguarding licence fee income and how it was spent, adding responsibility for green lighting new services.

The result was an internal regulator that failed to dispel the notion that it was hopelessly conflicted, as both regulator of and cheerleader for the national broadcaster.

Nor did it help that Grade jumped ship to ITV three months before the trust formally took charge of BBC governance in January 2007. From scandals about fakery and "Sachsgate" to executive pay, the BBC's acquisition of Lonely Planet, and more recently the Jimmy Savile crisis and redundancy payoffs, the trust has been accused by external critics of acting too slowly and timidly.

Concern about the trust has run across the parties. One of Jowell's successors as Labour culture secretary, Ben Bradshaw, told the Royal Television Society Cambridge convention in September 2009 that the trust was not "a sustainable model in the long term" because of its conflicting regulator/cheerleader role – a criticism he has repeated this week.

Where the trust has acted decisively – closing down digital education service BBC Jam, refusing permission for expansion into local TV – it has faced the ire of staff and supporters, who have complained of missed opportunities. The censure of the Middle East editor, Jeremy Bowen, over the impartiality and accuracy of a radio report and online article was particularly unpopular with the corporation's journalists.

Its first chairman, former Birmingham council chief executive Sir Michael Lyons, faced criticisms that he was not a heavyweight. But while Lyons urged Mark Thompson to clamp down on executive pay – the ex-director general spoke of "ferocious pressure" on this issue at the Commons public affairs committee hearing this week – the constitution of the BBC meant he had little actual power to make it happen. The PAC heard trust figures saying it wasn't their job to police redundancy payoffs – and claiming that they met with resistance from BBC management when they encouraged it to take action.